Sley movement for a weaving loom

Abstract: Weaving loom with a sley having a given weaving range, and provided with at least one first and one second sley leg (21; 22), respectively, for supporting the sley (2), said sley legs being arranged in the form of a deformable rectangle with hinge points at (A, B, C, D), and with a knee mechanism (10) for driving sley (2). The knee mechanism is rotatably connected to said sley leg (21), to the top side thereof, by means of a connecting rod (6), said sley legs being connected, at their respective base side, to a first and second reed rotary shaft (23; 24), both said reed rotary shafts (23; 24) running mutually parallel and being mounted on a cross girder (4).

Description: The present invention relates to a weaving loom having an improved sley movement. Weaving looms whose sley is driven by a knee mechanism are known. This knee mechanism is suitable for carrying out a sley movement with double beat-up. In Belgian Patent No. BE-895266 a weaving loom is disclosed in which the sley is provided with a pair of sley legs which are arranged in the form of a parallelogram support and the sley is further driven by such a knee mechanism which interacts with a cam. When the sley carries out a movement, the weaving reed maintains its vertical orientation during the oscillating beat-up movement, which takes place in the form of arcs on said sley legs with parallelogram support. Using the knee mechanism, a large beat-up pressure force can be effected with a limited drive torque on the cam, as is well known in the field of mechanical presses. However, a weaving loom of this kind has various disadvantages. In order to span a weaving width of large dimensions, this sley has to be designed such that it has great flexural stiffness, as only two drive points can be provided alongside the warp threads on both sides of the loom. Consequently, the sley has to be designed as a heavy girder supported by various parallelogram supporting legs which act as sley legs. Therefore, these sley legs do not contribute towards the flexural stiffness of the unit. In addition, the drive is only transmitted by two drive points which are located outside the fabric layer. This results in a considerable flexural strain on the sley. A sley construction of this kind is relatively heavy. This brings with it a high moment of inertia which has an adverse effect on the weaving speeds and, in addition, also generates vibrations of the ground. Document BE-900016 discloses a weaving loom which is provided with a sley with parallelogram support and direct cam drive. With this weaving loom, effecting a double beat-up movement by means of the design of the cam profile is very difficult. The drive of the sley takes place over a large width by the twisting moment of one single reed rotary shaft. This reed rotary shaft thus has to be dimensioned to be large in order to be able to transmit the required twisting moment. Furthermore, the cam drives have to be fitted under the fabric layer in order to reduce the torsion arm. Fitting the drive groups under the fabric layer is relatively complicated and makes access for any repair work relatively difficult. The object of the weaving loom according to the invention is to provide a solution for the abovementioned problems. To this end, the weaving loom comprises a sley having a given weaving range determined in accordance with the sley, and at least one first and one second sley leg, respectively, for supporting the sley. Said first and second sley legs, respectively, are arranged in the form of a deformable rectangle with hinge points at A, B, C, D. The weaving loom furthermore comprises a knee mechanism for driving said sley. According to the invention, said knee mechanism is rotatably connected to said at least one first sley leg, to the top side thereof, by means of a connecting rod, said first and second sley legs, respectively, being connected, at their respective base side, to a first and second reed rotary shaft, respectively, both said reed rotary shafts running mutually parallel and being mounted on a cross girder, which runs virtually parallel with said sley. The weaving loom according to the invention offers the advantage that the sley does not have to be very flexurally stiff. The flexural strain is converted, via the parallelogram sley supporting legs, to a twisting strain on the reed rotary shafts acting in parallel and mounted on a flexurally and torsionally stiff cross girder. The sley may have a smaller mass, even for large weaving widths. Higher weaving speeds can thus be achieved. Another advantage of the weaving loom according to the invention is that less vibrations are passed on to the ground. The flexural moment and torsional moment are absorbed by the reed rotary shafts which are mounted on said flexurally and torsionally stiff cross girder. Further embodiments are defined in the subclaims. Further advantages and details of the weaving loom will become clear from the following description of an illustrative embodiment with reference to accompanying drawings. Figure 1 is a schematic representation of a part of the weaving loom according to the invention. Figure 2 is a side view of the representation according to Figure 1 with the reed in the beat-up position. Figure 3 is a representation analogous to that of Figure 2 with the reed in the open position. Figure 1 shows a general perspective view of the part of a weaving loom in which elements according to the invention have been incorporated. The weaving looms in question are weaving looms which achieve great weaving speeds, which generate a large beat-up pressure force with a small drive torque on the drive mechanism 10, in particular a cam 11 as illustrated in Figure 1. The weaving loom is fitted on a frame 1 and is provided with a sley 2 which executes an oscillating beat-up movement in the form of arcs between a beat-up position and an open position. The sley movement takes place in such a manner that the weaving reed 3 maintains a virtually vertical orientation, at least in the final positions. The sley 2 is supported by a pair of elongated sley legs 21, 22 which extend transversely relative to the sley towards a cross girder 4, and are fixedly connected to the reed rotary shafts 23, 24 which are mounted on the cross girder 4. The sley legs are distributed along the longitudinal direction of the sley and are fixedly connected to reed rotary shaft 23, 24, respectively. Said reed rotary shafts are mounted on bearing blocks 5 on said cross girder, which runs virtually parallel with the sley. Figures 2 and 3 show a knee mechanism 10 in two different positions E, E', which serves as drive mechanism for the sley. As mentioned above, said knee mechanism is very suitable for a sley movement with double beat-up. Said knee mechanism interacts with a cam (and is known per se, as mentioned). The knee mechanism is hingedly connected on its one end to a connecting rod 6 which is directly connected to one of said first sley legs 21. The knee mechanism is thus mechanically connected to the sley via the sley legs 21. As a result, even with a limited drive torque on said cam, a large beat-up pressure force can be achieved by means of the knee mechanism, in which case the large beat-up pressure force produced can be transmitted to the sley via said sley leg. In order to distribute the beat-up pressure force over the weaving range of the weaving loom, two knee mechanisms are preferably provided, which are arranged at both longitudinal ends, respectively, of the sley, as illustrated in Figure 1. This results in a more regular and homogenous transmission of power. Figures 2 and 3 furthermore show that said first sley leg 21 interacts in each case with a second sley leg 22 and, more particularly, in the form of a deformable rectangle, preferably a trapezium with hinge points at A, B, C, D. The action of force absorbed by said first sley leg 21 is transmitted to said second sley leg 22 by means of this mutual rectangular arrangement of said first and second sley legs, respectively. Thus, a distribution of the flexural strain over the first and second sley legs 21 and 22, respectively, is achieved which is, in addition, converted to a twisting strain on both reed rotary shafts 23, 24 acting in parallel. Said reed rotary shafts are mounted on the flexurally and torsionally stiff cross girder 4, via bearing blocks 5. Consequently, the flexural moment and the torsional moment are absorbed by both parallel reed rotary shafts, which are mounted on said cross girder which is, in turn, both flexurally and torsionally stiff. Thus, the requirement of flexural stiffness of the sley becomes less stringent, i.e. the abovementioned problem of a very much higher flexural stiffness of the sley is thus solved. The sley can thus be constructed to have a smaller mass, even if a large weaving width is required. Due to the permitted smaller mass of the sley, the weaving speed can be increased significantly. A further advantage in this case is the fact that less vibrations are produced, which has a positive effect on the working environment. In this case, the two reed rotary shafts run uninterrupted at least over the entire width of the weaving range, as is shown in Figure 1. This results in an excellent transmission of the flexural moment and the torsional moment onto said cross girder 4. Furthermore, both reed rotary shafts are preferably mounted on one-piece bearing blocks 5 which are arranged at a regular distance from each other and are fixed to said cross girder. Preferably, both reed rotary shafts are fixed at one end in the main frame 1 and at the other end in one of said bearing blocks, as illustrated in Figure 1. The second reed rotary shaft 24 is fitted slightly higher than the first reed rotary shaft 23 relative to the cross girder 4. Sley leg 22 is therefore slightly shorter than sley leg 21, as a result of which the weaving reed is inclined slightly forward from the vertical position during the movement. With the beat-up movement, the bar will thus tend to be pushed down, as a result of which the chances of it breaking out are limited. In addition, the first and second sley legs 21, 22, respectively, are mutually axially displaced, in such a manner that the trapezium configuration ABCD is sufficiently flat, i.e. the height or distance between side AB and side CD is not too great. In this way, this mechanism can be constructed in a compact manner and the top side BC can move into the space under the work top 25 during the beat-up movement. Moreover, rolling bearings can be inserted in the bearing blocks 5 without the distance between the pivots A and D having to be increased. This permits the axles 23, 24 to be dimensioned large without the distance between A and D having to be increased. In the mutually axially displaced configuration of the first and second sley legs, respectively, one first sley leg 21 can be provided for each second sley leg 22, in each case upwards or downwards relative to the main frame 1, or alternately upwards and downwards. It is also possible to provide two first sley legs for a number of second sley legs, in which case one is arranged upwards and the other one downwards relative to the second sley leg 22, as is shown in Figure 1, in particular on both ends of the sley 2. One of the two second sley legs, in particular the two second sley legs arranged at the extreme ends, serves as a connecting piece for the transmission of the drive of both knee mechanisms 10 arranged there.

Claims: Weaving loom mounted on a frame (1) and provided with a sley (2) having a given weaving range determined in accordance with the sley, and provided with at least one first and one second sley leg (21; 22), respectively, for supporting the sley (2), said first and second sley legs (21; 22), respectively, being arranged in the form of a deformable rectangle with hinge points at (A, B, C, D), and provided with a knee mechanism (10) for driving said sley (2), characterized in that said knee mechanism (10) is rotatably connected to said at least one first sley leg (21), to the top side thereof, by means of a connecting rod (6), said first and second sley legs (21; 22), respectively, being connected, at their respective base side, to a first and second reed rotary shaft (23; 24), respectively, both said reed rotary shafts (23; 24) running mutually parallel and being mounted on a cross girder (4), which runs virtually parallel with said sley (2). Weaving loom according to Claim 1, characterized in that said first and second reed rotary shafts (23; 24), respectively, run uninterrupted at least over the entire width of said weaving range. Weaving loom according to Claim 1 or 2, characterized in that said knee mechanism (10) is hingedly connected to said first sley leg (21). Weaving loom according to one of Claims 1 to 3 inclusive, characterized in that said knee mechanism (10) is provided at both longitudinal ends thereof. Weaving loom according to one of the preceding claims, characterized in that said first and second sley legs (21; 22), respectively, are arranged in each case in the form of a deformable trapezium with hinge points at A, B, C, D. Weaving loom according to one of the preceding claims, characterized in that both said parallel reed rotary shafts (23; 24, respectively) are mounted on a pair of one-piece bearing blocks (5) which are arranged at a regular distance from each other. Weaving loom according to one of the preceding claims, characterized in that both said parallel reed rotary shafts (23; 24) are mounted at one end in the frame (1).

Inventors: DEWISPELAERE ANDRE, DEWISPELAERE, ANDRE, Dewispelaere, André
Applicants: WIELE MICHEL VAN DE NV, N.V. MICHEL VAN DE WIELE
Application year: 1994
Main classification: D03D49
IPC codes: D03D49